The present invention relates to a device for data entry into data processing machines, in particular computers. Currently, conventional keyboards perform this task.
Prior art (existing keyboards or their conventional variations) comprise an electronic circuit board, underneath a set of alphanumeric keys kept apart from the circuit board by a spring or similar device. Pressing a key down causes the electronic contact that will eventually translate into input data.
International publication, No. WO93/15538, discloses a touch sensitive panel having a front face with all the circuit elements on the rear face of the panel. This panel is typically used with industrial machinery.
U. K. patent application, No. GB 2279617 discloses a palmtop computer with an attached flexible film keyboard that can be folded behind the computer when not in use. Flexible film keyboards are not suited to being folded, however, as the flexible keys become stressed when folded, leading to less flexibility over time.
Moreover, flexible film or membrane keyboards require a gap between the membrane and the base of the keyboard, and therefore are not as thin as desirable for multiple foldability.
German patent, No. DE-A-2932540 consists of a liquid crystal display with a conductive plate cut out in certain sensor gratings. The patent focuses on creating a unique display on the LCD for each different sensor grating. This requires extra layers, for the LCD and other components that increase thickness.
One disadvantage of prior art keyboards is that the keyboards have to accommodate the circuit board plus the separating device (e.g., a spring) plus the keys, and therefore are relatively thick. It is not easy to substantially reduce thickness.
Another disadvantage of prior art keyboards is that to reduce the width and length, the keys must become smaller and the distances between the keys and the underlying circuit board reduced. Shrinking a keyboard to small or pocket size dimensions sacrifices convenience and speed of operationxe2x80x94especially for operators with large fingers and hands. In fact, beyond some point, a shrunken keyboard becomes impossible to operate.
Another disadvantage of prior art keyboards is that the circuit board, the keys, and the separating devices are housed in a box and preferably have a lid protecting the keys, resulting in heavier weight.
Another disadvantage of prior art keyboards is that keys can be stuck to adjacent keys and either have restricted movement or that pressing a key can cause adjacent keys to be pressed too.
Another disadvantage of prior art keyboards is that spilled drinks or solid particles can penetrate the gap formed between adjacent keys to the circuit board and disrupt the circuitry and/or glue that holds the keys together or to the circuit board.
Another disadvantage of prior art keyboards is that the spring mechanisms underneath the keys can become less responsive over time and lose their rebounding property.
Another disadvantage of prior art keyboards is the noise of operation. For example, using conventional keyboards in a quiet library or in a shared bedroom is not desirable.
Another disadvantage of prior art keyboards is that it is not easy to clean the keys, especially visible faces on and between keys, which do get dirty, especially in a dirty environment.
Another disadvantage of prior art keyboards is that since the keys have to be light and easy to press, they are generally not firm and bulky, and therefore are vulnerable to breakage. In other words, for transportation and use, keyboards should be treated as xe2x80x9cfragilexe2x80x9d, which is not very convenient considering their extensive daily use.
Another disadvantage of prior art keyboards is that the time required for data entry is not just the time required for an operator""s finger to touch a key. The time for each key to travel the distance to the underlying circuit board, plus often the time for the operator to feel the key""s rebound before next key is pressed, reducing speed, must also be considered.
Some of the above disadvantages do not apply to a type of keyboard currently used in, for example, fast food restaurant order entry and on some hand held calculators. In these keyboards the circuit board is separated from the keys by a bubble gap that is closed by pressing the keys surface. This surface is generally constructed of a material with spring-like properties that keep the key surface and circuit board separate (until pressure is applied to the key surface). The problem with this kind of keyboard is that the pressure needed to cause contact between the keys and the circuit board is relatively xe2x80x9chighxe2x80x9d making data entry slow and laborious.
There are other methods of data entry that when advanced and perfected in the future may reduce the need for keyboards, such as xe2x80x9cvoice recognitionxe2x80x9d and xe2x80x9chandwriting recognitionxe2x80x9d. Currently, however, these methods are slower than finger operated data entry.
It is desirable to have a finger operated data entry device that has the following properties:
It can be operated by touch, usually by an operator""s finger, so that higher speeds can be attained for data input;
All the symbols for recognition of a given entry are laid-out on a surface large enough for easy identification and operation;
The device can be small, light, sturdy, and portable; and
It does not have any or many of the disadvantages of the prior art keyboards listed above.
The present invention relates to a thin electronic data input device. Some versions of the input device may be foldable, and some versions are capable of being rolled up. Still other versions are capable of being disintegrated into smaller sub-parts. Other versions have one or more of these properties.
In one version of the invention, a thin electronic data input device for generating electrical signals for transmission to an electronic device, such as a computer, in response to an operator""s finger strokes is provided. The data input device comprises a thin circuit board made of a material on which thin electronic circuitry can be affixed, such as a printed circuit, as is well known to those skilled in the art. The electronic circuitry includes at least one node, electrically coupled to the circuit board, so that when touched by a finger, a unique signal associated with that node is transmitted to the electronic device or receiving processor or computer.
One standard way of achieving this is for the node to have a first portion and a second portion that are spaced apart and electrically isolated from each other by a narrow gap. If the gap is closed at that node, it will signal entry of particular symbol (letter, figure, etc.) to the receiver of data (usually, but not necessarily, a computer). The gap is usually bridged by the operator""s finger touching the gap and completing the circuit. As the human body conducts some electricity, bridging the gap by finger will cause some electronic flow that signals the particular node whose gap has been touched. In essence, the operator""s finger does what the pressed key in a conventional keyboard does.
In circumstances, where a human finger does not provide sufficient conductivity to connect the node gap, the operator can wear special conductive finger cups.
In another version of the invention, the data input device can be comprised of two or more sub-parts connected together by a hinge, or flexible joint along a common side or edge between adjacent sub-parts. Similarly the data input device can comprise more than two sub-parts that may fold on each other longitudinally and latitudinally, i.e., along one edge of a given sub-part, and along a subsequent edgexe2x80x94usually at 90xc2x0 to the first edge. A typical data input device may comprise multiple sub-parts folding longitudinally within each row and latitudinally along the edge of an extreme sub-part in each row.
The electronic circuitry will be coupled between sub-parts via flexible cables. These cables are preferably affixed on the same sides of the sub-part as the flexible joints. All this allows the data input device to fold to a smaller width and length and fit into a pocket of an operator.
One typical application is a keyboard version with a full size symbol set comprised of equal sub-parts in 3 rows of 4 sub-parts in each row. All the rows fold 4 times longitudinally, while the extreme sub-part along the respective edges of each row fold latitudinally. This provides for 12 folds that allow the data input device to easily fit into the pocket of an operator.
A thin layer of protective film, leaving only the nodes exposed for touch by an operator""s finger may cover the electronic circuitry.